The invention described herein was made in the course of, or under, a contract with the United States Atomic Energy Commission.
This application is a continuation-in-part of application Ser. No. 265,041 filed June 21, 1972, now abandoned. The present invention relates to a method of immobilizing radionuclide wastes in a stable, essentially non-leachable and non-dispersible form. More specifically, it relates to a method of immobilizing radionuclide waste in highly insoluble complex metalo-silicates.
A problem facing the nuclear industry which has received much attention is how to dispose of radionuclide wastes so that they will never contaminate the biosphere with radioactivity. Since all containers, no matter how complex, have a finite life which is short with respect to the halflife of plutonium (24,400 years), containerization of radionuclide wastes cannot be relied on alone for ultimate disposal of radionuclide waste. Acid environment should, of course, be avoided as a storage media where possible. Heretofore many attempts, all having differing drawbacks, have been made for immobilizing the radionuclide wastes, viz. .sup.137 Cs, .sup.90 Sr, .sup.239 Pu, .sup.241 Am, etc. Such attempts have included incorporation of radionuclide waste in phosphate glass, asphalt, concrete and in ceramic material of many kinds and storing the encapsulated material out of the biosphere in a salt or bedrock cavern. Even through the material formed in some of the suggested processes is quite insoluble, much is left desired in providing an effective bulk disposal process for immobilizing nuclear wastes.
With regard to waste disposal by encapsulation in mineral form which is virtually insoluble and placement in a similar mineral environment deep underground, one would approach an almost ideal mode of disposing of the highly dangerous radionuclide waste as a by-product by the nuclear industry.
Accordingly, it is an object of this invention to provide a method for the immobilization of radionuclides in virtually an insoluble non-leachable form.
Another object is to provide an economic and efficient method for immobilizing radionuclides, such as .sup.137 Cs, .sup.90 Sr.